This invention relates to bridging connectors and, in particular, to bridging connectors for use in facilitating the connection of subscriber lines from one main distributing frame to another in a telephone central office.
As is well known, in a telephone central office, wire conductors comprising subscriber lines are brought into the office and connected in groups to the back of a grid structure. The front of the grid structure is provided with pins each of which is electrically connected to a different one of the wire conductors of the subscriber lines. These pins provide electrical access to the subscriber lines and the switching equipment in the central office is thus connected to the lines through the pins.
In particular, the grid pins are usually arranged in adjacent rows of 16 pins with adjacent pins in the rows being connected to the tip and ring conductors of a given subscriber line. A plug connector then connects this grid pin group to a corresponding group of pins adapted to receive wire wrapping, i.e., to so called wire wrap pins. More specifically, the plug connector has on one face adjacent rows of female sockets and on another face adjacent rows of wire wrap pins which are electrically connected to the sockets. Connecting the female sockets of the plug connector to the grid pins thus electrically connects the adjacent rows of wire wrap pins to the grid pins and, therefore, to the subscriber lines.
Final connection of the subscriber lines to the central office main frame is through the wire wrap pins. Individual wire lines are wrapped around each pin. These lines are then formed into a cable and the cable brought to the main frame. The lines are then appropriately connected to the frame.
In a typical central office there are a large number of the aforementioned plug connectors providing connection of subscriber lines to the main frame. As a result, if the subscriber lines have to be connected from the existing main frame to a new main frame because of an upgrading of the telephone plant, the procedure for disconnecting the lines from the old frame and reconnecting the lines to the new frame becomes tedious and time consuming. It also results in down time for the subscribers.
In the presently existing procedure, a second set of wires is wired to the wire wrap terminals of each plug connector above the original wiring. This second set of wires is formed into a further cable which is to be connected to the new main frame. After the terminals are wrapped with the second set of wires, testing of the new wires and wire wrapped connections is carried out. Once all testing proves positive, the subscriber lines are placed out of service, while the new main frame is brought into service. Thereafter, the subscriber lines are again placed in service and finally the old wiring to the old frame is removed from the wire wrap terminals.
As above-indicated, the above procedures are quite tedious and, therefore, time consuming, and furthermore result in down time for the subscriber. In particular, when wiring the second set of wires above the original set, the craftsman must be extremely careful so as to not disturb the original wiring which still is being used to give the subscriber service. Furthermore, a similar tedious operation is encountered when removing the original wiring. Also, testing of the second set of wires is difficult, since the dual wiring on the wire wrapped pin leaves little room for conventional testing probes. The subscriber additionally experiences downtime when the new main frame is brought into service.
It is therefore a primary object of the present invention to provide a connector which facilitates changeover of subscriber lines from one main distributing frame to another in a telephone central office.
It is a further object of the present invention to provide a connector which permits changeover of subscriber lines from an old to a new main frame on a plug-out, plug-in basis.